X70管线钢超声波检测不合格原因及对策

Causes and Countermeasures for the Inconformity of Ultrasonic Testing of Pipeline Steel X70

通过金相显微镜、扫描电镜和能谱等技术手段,剖析了X70管线钢超声波检测不合格的原因。研究结果表明:超声波检测不合格是钢管心部夹渣所致。通过优化连铸机的拉速、浸入式水口浸入深度的工艺策略,X70管线钢超声检测合格率由96%提高至100%。

The causes of the inconformity in ultrasonic testing of X70 pipeline steel were analyzed by means of the metallurgical microscope,scanning electron microscope and energy spectrum.The results show that the inconformity of ultrasonic testing is caused by slag inclusions in the center of steel pipe.The qualified rate of ultrasonic testing of X70 pipeline steel has been increased from 96%to 100%by optimizing the casting speed of the caster and the immersion depth of the submerged nozzle.